Articulated bundle conductor spacer



Nov. 12, 1963 c. B. RAWLINS ARTICULATED BUNDLE CONDUCTOR SPACER Filed Aug. 1'7, 1960 INVEN TOR.

CHARLES B. RAWLINS ATTORNEY United States Patent Oii ice 3,110,757 ARTICULATED BUNDLE CONDUCTOR SPAQER Charles B. Rawlins, Massena, N .Y., assignor to Aluminum Company of America, Pittsburgh, Pa., a corporation of Pennsylvania Filed Aug. 17, 1960, Ser. No. 50,205 4 Claims. (Cl. 174-123) This invention relates to spacer devices employed in conjunction with multiple parallel conductors preferably and normally constituting a single phase of an electrical transmission circuit.

Bundle conductors, which is a term applied to suspended groups of multiple parallel-spaced conductors, each group comprising one of the phases of a transmission circuit, are becoming increasingly popular inpreference to installations employing [one conductor per phase, particularly in high voltage electrical energy transmission systems, with many electrical advantages attributable thereto. For example, corona loss has been observed to be reduced as much as 34 percent through the substitution of twin single phase parallel-spaced conductors for a single line conductor of substantially the same capacity. In addition, bundle conductors reduce surge impedance, with the result that line transmission capacity may be considerably increased.

Regardless of the improved electrical advantages gained from the substitution of bundle conductors for single-conductor installations, certain mechanical problems have been presented which have had to be solved. Chief among the mechanical problems was positive separation of the individual conductors, within a bundle 'of the same, to avoid wind-induced and electromagneticallyinduced contact and interlocking engagement therebetween.

An object of the invention is to provide a spacer of sufficient mechanical strength to insure and maintain a predetermined and desired spacing between parallel runs of suspended conductors while the latter are subjected to loads imposed'by external forces induced by normal and abnormal flow of electrical energy through the parallel conductor runs, or imposed by meteorological efiects such as wind and ice.

Another object of the invention is to provide a spacer having suflicient flexibility to permit relative motion of parallel conductor runs in respect of their overhead supporting means and the spacer separating the same in its clamping attachment to each of the parallel conductors, without inducingdetrimental stresses in the conductors of intensities capable of developing mechanical failures adjacent the points of clamping attachment of the spacer to the conductors.

A further object is to' provide a spacer characterized by sufficient rigidity to maintain the desired predetermined conductor spacing, while providing the flexibility characteristics essential to relieve undue mechanical stresses in the spacer elements resulting from relative movements of the spaced conductors in the directions of their axes.

It is also an essential object to the success of spacers falling within the scope of the invention that the elements thereof, constituting clamping attachment of the spacers to parallel runs of conductors, provide intimate and firm electrical contact with the conductors and exert sufficient substantially constant pressure the'rebetween to avoid development of varying electrc-potentials between the contacting surfaces of the spacers and conductors in the event of different generated voltageswithin the conductors.

Other objects and advantages of the spacer of the invention will be understood by one skilled in the art from consideration of the following description and illustrations, in which:

FIG. 1 represents a top plan view of one embodiment of the spacer of the invention with one element of a conductor clamping member removed;

FIG. 2 represents a fragmentary transverse sectional view of the spacer of FIG. 1;

FIG. 3 represents a top plan view similar to P16. 1 of a second embodiment of the spacer of the invention;

FIG. 4 represents a fragmentary transverse sectional view of the spacer of FIG. 3.

FIG. 5 represents a sectional view taken on the plane V-V of FIG. 1; and

FIG. 6 represents a sectional view taken on the plane VIVI of FIG. 3.

In general, spacers of the invention insure a clear space of substantially twelve to twenty inches between individual conventional conductors constituting bundles of the same, with which spacers of the invention have been employed. The spacer must also provide articulated connection and attachment between its conductor engaging elements and a spacer bar thenebetween to permit relative movement of the individual conductors in a bundle of the same parallel to their axes.

Spacers constructed in accordance with the invention have been tested and have proved to be economical to manufacture and efficient in performance.

Broadly speaking the preferred spacer devices of the invention comprise separable clamping elements for clamping attachment to each conductor in a bundle of the same, the affixed clamping elements being separated by a relatively rigid spacer bar connected thereto through the medium of articulated joint connections. A significant feature of the spacer devices of the invention is the selection of the spacer bars thereof in the form of built-up leaf spring structures which react in allixation and normal use of the spacer devices to bias or exert a separating force on the conductor-clamping elements thereof out of their intended engagement with the conductors or cables clampingly engaged thereby. A further and cardinal feature of the preferred spacer devices of the invention is the selection of the articulated joint connections between the spacer bars and cable or conductor-clamping elements in the form of pintle members or bearing plugs having axi-symmetric bodies attached to the terminal ends of the spacer bars and having monotonically diminishing diameters with increasing distance from a major diameter adjacent their supporting attachment on the terminal ends of the spacer bar structures, the pintles or bearing plugs being otherwise received within substantially complementary bearing sockets in the conductor-clamping elements.

Twin conductor spacer devices have been selected for purposes of illustrating and describing the invention, but I in pairs by means of articulated connections to the ter-' minal ends of a rigid and relatively stifr" built-up leaf spring spacer or distance bar 12.

Each of the clamping members 10 comprises a pair of substantially identical electrically-conductive shellshaped elements 14 providing a substantially spherical exposed surface in over and under paired relationship thereof. The shell-shaped elements 14 are preferably, although not necessarily, fabricated as castings or forgings and are interiorly configurated by conventional coring or metal-displacing practices to provide opposed and aligned laterally spaced curvilinearly grooved wall portions 16 of each shell member for receiving and engaging a conductor 13 between a pair of the elements. Each shell ele- Patented Nov. 12, 1963 v ment 14 is also interiorly configurated to provide an internal boss 20, the purpose of which will be hereinafter explained, centrally located and inwardly offset in respect of the aforesaid grooved wall portions 16, exterior surface depressed areas 22, also inwardly located in respect of the grooved wall portions 16, being provided to receive the heads and/ or nuts of connecting bolts or threaded machine elements 24 extending through aligned apertures in each of the elements 14 disposed in axial alignment with the depressed areas 22.

In the embodiment of the invention illustrated in FIGS. 1 and 2,, one of the shell elements '14 of each over and under pair of the same is preferably threaded in respect of the bolt members 24, thus eliminating the necessity of employing separate nuts in securing the clamps on the cables 18.

The distance or spacer bar '12 of the embodiment of the spacer device of FIGS. 1 and 2 is constructed from two identical leaf spring elements which have each been preformed to provide a centrally located flat bearing area 30 and an inclined length 32 contiguous therewith on both sides thereof, as best shown in FIG. 2. The two leaf spring elements are unitarily secured by suitable fastening elements, such as the rivets 34, in abutting contact of their centrally located fiat bearing areas to provide the included acute angle A between their outwardly diverging inclined extensions 32. The aforesaid two leaf spring elements may also be joggled or offset as fabricated adjacent their terminal ends, as illustrated at 36.

The outwardly diverging disposition of the extending leg portions 32 of the spacer or distance bar 12 (FIG. 2) represent the bar in its unloaded condition, and axi-symmetric pintles or bearing plugs 40, having major diameter bases contiguously adjacent and monotonically diminishing or decreasing diameters in increasing distance from their major base diameters, are unitarily secured in the plane of their major base diameters to each terminal end of the built-up leaf spring elements constituting a spacer bar 12, the axes of the pintles 44! being substantially normal to the olfset outwardly disposed surfaces 36 thereof. The aforesaid axi-symmetric bearing plugs or pintles 40 are preferably selected from high quality wear-resistant bearing materials, such as compacted oil-retaining metallic powders, self-lubricating synthetic plastics, or bronze or iron bearing alloys.

Truncated conical pintles 40 have been selected for purposes of illustrating the invention and each is received within a complementary conical bore in the bosses provided in each clamping shell 14, a rivet or similar fastener 42 extending axially through each pintle 4t), and suitably headed at each end, serving to secure a clamping shell 14 in terminal attachment to each end of each of the two leaf spring elements of the spacer bar 12.

The above-described connections of the shells 14 to the terminal outboard ends of the leaf springs permit relative oscillatory movement of the shells and terminal end portions of the leaf springs supporting the same in respect to the axes of the pintles 40 and aligned conical bores in the bosses 20, the pintles within the conical bores constituting a freely oscillatable articulated connection between the spacer bar 12 and clamping shells 14'.

Attachment and mounting of the spacer device of FIGS. 1 and 2 to the twin conductors 18 requires inward compression of the normally outwardly diverging extending legs 32 of the leaf spring elements of the distance bar 12 to carry therewith the shells 14 attached thereto into clamping engagement of their grooved wall portions 16 on the exposed surfaces of the twin conductors 18. Bolts 24 are then threadedly engaged within the aligned threaded apertures in the lower shell 14 (FIG. 2) and are driven home therein to securely and unitarily assemble the spacer device on the twin conductors. A resilient washer 44 of natural or synthetic rubber, fiber, or equivalent synthetic plastic material is preferably employed in against accidental extractionor propulsion from the upper shell member 14 (FIG. 2) prior to or during installation of the spacer device.

It will be appreciated from the foregoing description that assembly or installation of the spacer device on the twin conductors 18 serves to load the leaf spring spacer bar 12 with the result that the truncated pintles 40 are mechanically biased into the complementary conical bores or sockets receiving the same. The spring loaded biasing action thus produced reacts to insure continuous bearing contact between the leaf springs and clamping shells carried thereby during normally-encounted relative conductor movements. The aforesaid biased mounting of the shells and leaf spring elements also insures continuous bearing contact between the truncated pintles 40 and their conica-l bores or sockets to take up any wear therebetween as a result of shock-induced loading and articulated relative movement between the shell clamping elements "14, distance bar 12 and twin conductors 18.

A second embodiment of spacer device falling within the scope of the invention is illustrated in FIGS. 3 and 4 and differs from that of FIGS. 1 and 2 only in the con struction of its spacer or distance bar 50 and manner in which the cable-engaging clamping members are oscillatably connected thereto to provide articulated jointure therebetween. In this instance the spacer bar 50 is again constructed from two identical leaf springs which are separated medially of their length by a spacer plate 52 through which the individual leaf springs are securely and unitarily attached in over and under relationship by rivets or similar fasteners 54.

As in the previous embodiment, the leaf springs constituting the spacer bar 59 are each preformed with outwardly extending axial lengths or legs 56 inclined in respect to a central fiat portion thereof and are unitarily assembled with the central spacer 52 to provide the outwardly diverging contained or included acute angle B therebetween, in an unloaded condition of the spacer bar 50. It is to be observed in this connection that the leaf springs are not joggled or offset adjacent their ends, as in the spacer device of FIGS. 1 and 2, and that the thickness of the central spacer plate 52 is substantially the equivalent of the distance between the oppositely disposed under surfaces of the ofiset lengths 36 in the loaded condition of the spacer device of FIG. 2.

Truncated cone bearings or pintles 60 (FIG. 4), unitarily attached to the terminal ends of each leaf spring, differ from their counterparts 40 (FIG. 2) only in their attachment to the clampingshell elements, the latter being substantially identical to those of FIG. 2. In this respect, the pintles 60 are peaned or headed adjacent their small ends to provide positive attachment to each of the clamping shells in this embodiment, it being desirable in such construction to employ metallic cone bearings 60 to insure a positive connection by the rivetting or heading operation.

Assembly or installation of the spacer device of FIGS. 3 and 4 is carried out in the same manner as described for the spacer device of FIGS. 1 and 2, with structural elements common to both embodiments of the invention being identified by similar reference numerals.

The loaded condition of spacer bar 50, in the embodiment of the invention illustrated in FIGS. 3 and 4, produces the same resiliently biased articulated connection between the spacer bar and conductor-engaging clamping elements described above in connection with the spacer device of FIGS. 1 and 2.

g It will be appreciated that the truncated conical pintles or bearing blocks 40 and 60 are representative of a general class of bodies which will serve equally well in the articulated connections between the conductor-clamping elements and spacer bars of the invention, hemispherically shaped and right cone bodies having axi-symmetric,

monotonically decreasing diameters in increasing distance from their major base diameters being essential to the success of the invention.

The spacer device of FIGS. 3 and 4 may be further ,rnodified by substituting rigid fiat steel bars for the preformed leaf springs of bar 50, and a resilient central loading spring for the spacer plate 52, which would provide and develop the same outward or biasing separating effect on afiixation of the conductor-engaging clamping elements on their parallel conductors. I

In the interest of reducing corona loss to a minimum, in bundle conductor installations employing the spacer devices of the invention, it is desirable that the exposed surfaces of the clamping shells 14, and elements of the spacer bars 12 and 50, be devoid of angular or sharp edges conducive of corona formation areas. In this connection the clamping shell elements 14 are preferably sand-blasted and/or ground to remove sharp changes in their otherwise substantially spherically-defining exposed.

surfaces, and the spacer bars 12 and 50 slightly rounded, as illustrated in FIGS. 5 and 6, along their marginal edges. The depressed surface areas or pockets 22 are also smoothly blended in their formation to avoid sharp angular surface changes in the otherwise smooth curvilinear exposed surface configuration of the clamping shell elements 14, and serve to prevent protruding surface exposure of the sharp angular bolt heads and/or nuts received therein, which would otherwise be a source of corona discharge.

Tests conducted on twin conductor spacer installations I of the invention have been observed to produce stability in spacing of the individual twin conductors, while permitting substantial movement of the conductors parallel to their axes, and the biased pintle and socket articulated connections between the clamping shell elements and their leaf spring distance spacer elements have been observed to maintain excellent electrical contact, with minimum generated radio influence.

Having fully described selected embodiments of spacer devices falling within the scope of the present invention,

what is desired to be claimed as patentably novel is defined in the following claims.

I claim:

1. A bundle conductor spacer including paired conductor-clamping shells attached to opposite ends of a distance bar device, said distance bar device comprising a pair of substantially similar elongated fiat leaf springs in superimposed assembly and unita-rily attached centrally of their length, the unattached axial lengths of the leaf springs being deflected away from each other to normally define an outwardly diverging included angle therebetween in unloaded condition of the leaf springs, a truncated cone pintle unitarily attached to each end of each leaf spring adjacent its terminal ends outboard of the central attachment of the leaf springs, said pintles having their axes substantially normal to the outwardly facing flat end surfaces of the leaf springs with the major diameter thereof adjacent the leaf springs, a complementary conical bearing socket within each clamping shell for'receivin'g one of the truncated cone pintles, means for axially interconnecting each of the pintles within its socket and constituting articulated connections between one each of the clamping shells and one each of the deflected ends of the leaf springs, said pintles in each pair of shells, in restrained clamping relationship of each pair of shells on a conductor, constituting outward resiliently biased seating of the pintles Within their conical sockets in a common axis of articulation of the distance bar relative to each of the paired clamping shells with the leaf springs in loaded condition, and separate means interconnecting each pair of conductor-clamping shells for drawing and restraining the same on spaced conductors therebetween.

2. A bundle conductor spacer comprising separable paired conductor-receiving and clamping elements, a distance bar separating said separable paired conductorreceiving and clamping elements, said distance bar comprising a pair of substantially similar lineally coextensive superimposed fiat leaf springs in unitary substantially central attachment with their terminal ends normally diverging away from each other to define an included acute angle therebetween, a pintle bearing member unitarily secured to each of the terminal ends of the superimposed =fiat leaf springs, each said pintle bearing being axi-sym-metric and having a major base diameter contiguous with the flat leaf spring supporting the same and having a monotonically decreasing diameter in increasing distance normal to and outwardly away from the major diameter thereof, each pintle bearing being received within a substantially complementary bearing socket in one element of each of the paired conductorreceiving and clamping elements, means interconnecting and axially securing each pintle bearing within its substantially complementary socket, and separate means interconnecting the separable paired conductor-receiving and clamping elements vfor drawing the same into clamping attachment on one end of two spaced conductors, whereby the normally diverging terminal ends of the superimposed flat leaf springs are sprung towards each other and the pintle bearings are resiliently axially unged outwardly into their complementary sockets on articulated assembly of the distance bar and interconnected paired clamping conductor-receiving and clamping elements on clamping attachment thereof on spaced conductors.

3. A bundle conductor spacer comprising separable paired 'conductonreceiving and clamping elements, a distance bar separating said separable paired conductorreceiving and clamping elements, said distance bar comprising a pair of substantially similar lineaily coextensive superimposed flat leaf springs in unitary substantially central attachment with their terminal ends normally diverging away from each other to define an included acute angle therebetween, a truncated cone pintle bearing member unitarily secured to each of the terminal ends of the superimposed fiat leaf springs 'with the major diameter flush with the outwardly facing flat end surface thereof and being received within a substantially complementary conical bearing socket in one element of each of the paired conductor-receiving and clamping elements, means interconnecting and axially securing each truncated cone pintle bearing within its substantially complementary conical socket, and separate means interconnecting the separable paired conductor-receiving and clamping elements for drawing the same into clamping attachment on one each of two spaced conductors, whereby the normally diverging terminal ends of the superimposed fiat leaf springs are sprung towards each other and the truncated cone pintle bearings are re.- siliently axially urged outwardly into their complementary conical sockets on articulated assembly of the distance bar and interconnected paired clamped conductor-receiving and clamping elements on clamping attachment thereof on spaced conductors.

4. A bundle conductor spacer comprising separable paired conductor-receiving and clamping elements, a distance bar separating said separable paired conductorreceiv-ing and clamping elements, said distance bar comprising a pair of substantially similar lineally coextensive superimposed flat leaf springs in unitary substantially central attachment with their terminal ends normally diverging away from each other to define an included acute angle therebetween, a pintle bearing member unitar-ily secured to each of the terminal ends of the superimposed flat leaf springs, said pintle bearing being axisymmetric and having a major base diameter contiguous with the flat leaf spring supporting the same and having a monotonically decreasing diameter in increasing distance normal to and outwardly away from the major diameter thereof, each pintle bearing being received within a substantially complementary bearing socket in one element of each of the paired conductor-receiving and clamping elements, means interconnecting and axially securing each pintle bearing within its substantially complementary socket, and separate means interconnecting the separable paired conductor-receiving and cl-amp- 5 ing elements for drawing the same into clamping attachment on one each of two spaced conductors, said interconnected pintles and sockets constituting articulated connections to each conductor-receiving and clamping eles ment and on clamping attachment on spaced conductors providing a common axis of articulation at each end of the distance bar.

References Cited in the file of this patent UNITED STATES PATENTS 1,488,879 Hester Apr. 1, 1924 2,973,402 Taylor Feb. 28, 1961 FOREIGN PATENTS P10,108 Germany Mar. 8, 1956 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Nov 3, 110 1 757 November 12, 1963 Charles B. Rawlins It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below Column 6, line 21, for "end" read each line 27, for "clamping" read clamped Signed and sealed this 28th day of April 1964.

(SEAL) Attest:

ERNEST W. S WIDER EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

2. A BUNDLE CONDUCTOR SPACER COMPRISING SEPARABLE PAIRED CONDUCTOR-RECEIVING AND CLAMPING ELEMENTS, A DISTANCE BAR SEPARATING SAID SEPARABLE PAIRED CONDUCTORRECEIVING AND CLAMPING ELEMENTS, SAID DISTANCE BAR COMPRISING A PAIR OF SUBSTANTIALLY SIMILAR LINEALLY COEXTENSIVE SUPERIMPOSED FLAT LEAF SPRINGS IN UNITARY SUBSTANTIALLY CENTRAL ATTACHMENT WITH THEIR TERMINAL ENDS NORMALLY DIVERGING AWAY FROM EACH OTHER TO DEFINE AN INCLUDED ACUTE ANGLE THEREBETWEEN, A PINTLE BEARING MEMBER UNITARILY SECURED TO EACH OF THE TERMINAL ENDS OF THE SUPERIMPOSED FLAT LEAF SPRINGS, EACH SAID PINTLE BEARING BEING AXI-SYMMETRIC AND HAVING A MAJOR BASE DIAMETER CONTIGUOUS WITH THE FLAT LEAF SPRING SUPPORTING THE SAME AND HAVING A MONOTONICALLY DECREASING DIAMETER IN INCREASING DISTANCE NORMAL TO AND OUTWARDLY AWAY FROM THE MAJOR DIAMETER THEREOF, EACH PINTLE BEARING BEING RECEIVED WITHIN A SUBSTANTIALLY COMPLEMENTARY BEARING SOCKET IN ONE ELEMENT OF EACH OF THE PAIRED CONDUCTORRECEIVING AND CLAMPING ELEMENTS, MEANS INTERCONNECTING AND AXIALLY SECURING EACH PINTLE BEARING WITHIN ITS SUBSTANTIALLY COMPLEMENTARY SOCKET, AND SEPARATE MEANS INTERCONNECTING THE SEPARABLE PAIRED CONDUCTOR-RECEIVING AND CLAMPING ELEMENTS FOR DRAWING THE SAME INTO CLAMPING ATTACHMENT ON ONE END OF TWO SPACED CONDUCTORS, WHEREBY THE NORMALLY DIVERGING TERMINAL ENDS OF THE SUPERIMPOSED FLAT LEAF SPRINGS ARE SPRUNG TOWARDS EACH OTHER AND THE PINTLE BEARINGS ARE RESILIENTLY AXIALLY URGED OUTWARDLY INTO THEIR COMPLEMENTARY SOCKETS ON ARTICULATED ASSEMBLY OF THE DISTANCE BAR AND INTERCONNECTED PAIRED CLAMPING CONDUCTOR-RECEIVING AND CLAMPING ELEMENTS ON CLAMPING ATTACHMENT THEREOF ON SPACED CONDUCTORS. 